Stoker apparatus



I Dec. 25, 1945. STONE STOKER APPARATUS Filed Sept. 6, 1944 WITNESSES:

.BY W'. M

ATTORNEY Patented Dec. 25, 1945 STOKER APPARATUS Earll R. Stone, Lansdowne, Pa., assignor to West-' inghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application September 6, 1944, Serial No. 552,874

6 Claims.

This invention relates to stokers, more particularly to moving grate structures thereof, and has for an object to provide improved action for such grates.

Another object of the invention is to provide a grate construction including bars of the inverted-V type having pivotal joints at their apexes, together with novel means for imparting to said bars motion having both horizontal and vertical components.

A. further object of the invention is to provide novel toggle linkage for imparting vertical and horizontal movement to the fuel-supporting surface of a stoker to progressively feed fuel thereover.

These and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. l is a transverse sectional view through stoker apparatus embodying the features of the present invention; and, V

Fig. 2 is a view similar to Fig. 1, but showing the moving parts of the apparatus disposed in a different position.

Referring now to the drawing more in detail, the reference character In indicates, in its entirety, stoker grate mechanism comprising a plurality of reciprocable grate bars II of inverted-V formation disposed, preferably alternately, in side-by-side relation with a plurality of stationary grate bars I2, likewise of inverted-V formation, Both the stationary and reciprocable bars have their outer ends resting upon wear plates I3 disposed in overlying relation to the inner ends of conventional dump plates I4 disposed above the usual side ash pits I 6.

The stationary bars I2 are provided, intermediate their ends, with depending foot members I! adapted to rest upon plates I8 supported by structural members I9, the feet I I having depending lugs 2| disposed at opposite sides of the plates I8, thereby preventing transverse reciprocation of the stationary bars I2.

The reciprocatoiy bars I I are provided at their apexes with pivotal joints 22 from which depend levers 23 pivotally connected intermediate their ends, at 24, with one end of supporting links 26. These links 26 are pivotally supported at their other ends, at 21, to fixed supports 28, bolted or otherwise secured to suitable supporting structure such as the structural member I9,

The lower ends of the levers 23 are pivotally connected, as at 29, with the upper ends of levers 3I whose lower ends are pivotally supported, as at 32, from fixed supports 33.

Driving links 34 are pivotally connected at one end to the pivotal connection 29 of the adjacent ends of the levers 23 and 3I, and have their other ends pivotally secured, as at 36, to crank arms 31 fixedly secured on an oscillatory shaft 38 extending from front to rear of the furnace grate structure in parallel relation to the axes of the previously mentioned pivotal connections 22, 24,21, 29 and 32.

In operation, fuel is adapted to be fed rearwardly through the opening M in the furnace front wall 42 by suitable means such as the impeller blades 43 of the rotary impeller 44. The

fuel thus fed into the furnace falls onto the central portion of the grate structure which extends from front to rear of the latter and includes approximately the central third of the width thereof. The fuel thus deposited on the central lane by the spreader mechanism is adapted to be fed laterally therefrom to the dump plates I4 by the reciprocatory motion of the movable grate bars lI. It will be apparent that such motion is imparted to the movable grate bars II through the toggle linkage providing the driving connection between the oscillatable shaft 38 and the grate bars.

As the shaft 38 is oscillated between'the limits indic'atedby the full and dot-dash lines of Fig. 2,

the lever 23 will be moved between the limits likewise indicated in Fig. 2, with the result that the reciprocatory bars I I are moved from a position where the right-hand end thereof, as viewed in the two figures, projects beyond the stationary bars, to the opposite extreme where the righthand ends of the reciprocatory bars are retracted between the adjacent stationary bars, as indicated at the left in Fig. 2. When the reciprocatory bars II are at the two limits of their motion, it will be apparent that the apexes thereof are disposed below the corresponding apexes of the adjacent stationary bars, However, when the reciprocatory bars I I are at the mid point of their motion, their apexes will project above the corresponding apexes of the adjacent stationary bars I2, as best indicated in Fig. 1. It will be apparent, that this novel motion having both horizontal and vertical components, is obtained by the use of the novel toggle linkage 23 and 3I, herein illustrated, together with the floating fulcrum or pivot 24 for the upper lever 23.

It will also be apparent that variations in the amounts of vertical and horizontal components of grate bar motion may be obtained by varying the are through which the shaft 38 oscillates, by varying the lengths of lever 23 or 3|, or by shifting the fulcrum 24 lengthwise of the lever 23.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What is claimed is:

1. In a stoker, a plurality of grate bars of inverted-V type disposed in side-by-side relation and providing a pair of fuel-supporting surfaces inclined downwardly in opposite directions from a central apex, a number of said grate bars being reciprocable and interspersed among the remaining bars, which are stationary; means providing a pivotal joint at the apex of each of said reciprocatory bars; supporting means on which the outer ends of the bars are adapted to rest with the reciprocable bars slidable thereon; and means supporting the reciprocable bars intermediate their ends and adapted to transmit motion thereto having both horizontal and vertical components.

2. Structure as specified in claim 1, wherein the last-mentioned means comprises a plurality of pairs of vertical levers with the levers of each pair pivotally connected in end-to-end relation, a fixed pivotal support for the lower end of each lower lever, means pivotally connecting the upper end of each upper lever to one of the movable grate bars, a vertically movable fulcrum for each upper lever intermediate its ends, and means for oscillating said upper levers about said fulcrums. 3. Structure as specified in claim 1, wherein the last-mentioned means comprises toggle linkage including a plurality of first levers pivotally connected at their upper ends to the pivotal joints of the reciprocable bars, a plurality of second levers pivotally connected at their upper ends to the lower ends of the first levers, fixed pivotal supports for the lower ends of the second levers, a plurality of links pivotally connected at one end to the first levers intermediate the ends of the latter, fixed pivotal supports for the other ends of said links, and means for imparting oscillatory motion to the first levers about their pivotal connections with the links.

4. Structure as specified in claim 1, wherein the last-mentioned means comprises a plurality of first levers pivotally connected at their upper ends to the pivotal joints of the reciprocable grate bars, a plurality of second levers pivotally connected at their upper ends to the lower ends of the first levers, means pivotally supporting the lower ends of said second levers, means providing a floating fulcrum for the first levers intermediate their ends, an oscillatable driving shaft disposed in parallel relation to the axes of the previouslymentioned pivotal connections, crank arms fixedly mounted on the shaft, and driving links for transmitting oscillatory motion from the outer ends of the crank arms to the pivotally-connected first and second levers for movement of said first levers about their floating fulcrum.

5. In a stoker, a plurality of grate bars of inverted-V type disposed in side-by-side relation and providing a pair of fuel-supporting surfaces inclined downwardly in opposite directions from a central apex; a pivotal joint at the apex of each of a plurality of said bars; and means for imparting reciprocatory motion to said jointed bars and for simultaneously raising and lowering the apexes thereof, said means comprising a plurality of toggle mechanisms each including a first lever pivotally connected at its upper end to the pivotal joint of a grate bar thereabove, a fixed support, a second lever pivoted at its lower end to said fixed support, means pivotally connecting the levers at their free ends, means providing a fulcrum for the first lever intermediate its ends, and means adapted to oscillate said first and second levers about the fulcrum and the fixed support, respectively.

6. In a stoker, a plurality of grate bars of inverted-V type disposed in side-by-side relation and providing a pair of fuel-supporting surfaces inclined downwardly in opposite directions from a central apex, a plurality of said grate bars being reciprocable; means providing a pivotal joint at the apex of each of said reciprocable bars; supporting means on which the outer ends of all of the bars are adapted to rest with the reciprocable bars slidable thereon; and means supporting the reciprocable bars intermediate their .ends and adapted to transmit motion thereto having both horizontal and vertical components.

EARLL R. STONE. 

